Grain-polishing machine

ABSTRACT

A grain-polishing machine having a grain-polishing chamber of a cross-sectional configuration with more than six angles, which allows a grain-polishing roller rotatably mounted within said chamber to be of a comparatively large diameter and hence to be driven by a motor of high horsepower, whereby its polishing efficiency is considerably increased compared to a conventional grain-polishing machine of the kind.

[561 References Cited UNITED STATES PATENTS 3,401,731 9/1968 Wayne 3,435,865 4/1969 Mori...... 3,485,280 12/1969 Satake........................... Primary Examiner-William S. Lawson Attarney-Browdy and Neimark Toshihiko Santn No. 2-38, Nishihonmachi, Saijyo-Mnchi, Malmo-gun, Hiroshima-ken, Jnpnn 887,241 lDec. 22, 1969 Patented Dec. 2l, 19711 2 Cllmims, 4l Drawing Figs.

[Jnmd Stam@ Pnmm [72] Inventor [2l] Appl. No.

[22] Filed [54] GMAIIN-TPOILIISHIING MACHINE of the kind.

mmfnuacm mn 3628582 SHEET l UF 2 FIG? INVENTOR BY f//A ATTORNEYS' MTENTEU BEEN Wil SHEET 2 UF 2 ATTORNEY 5 GRAlN-POLISI-IING MACHINE This invention relates to a grain-polishing machine. It relates to, more particularly, a rice-polishing machine which can be driven by a motor having a comparatively large capacity whereby high-rice polishing efficiency is obtainable.

Hence, it is a principal object of the present invention to provide a rice-polishing machine which'can efficiently polish in a unit of time such an amount of rice that can normally be polished by utilizing two or more conventional rice-polishing machines.

lt is well known that productive capacity of a conventional rice-polishing machine is in proportion to the capacity or horsepower of an electric motor provided to the machine. For instance, to a conventional rice-polishing machine mounted with a polishing roller of 137 mm. in its outer diameter, a l5 to 20 hp. motor is provided. The polishing capacity of this machine would be 1,200 kg. of rice per hour since productive capacity of l horsepower is equivalent to 20 kg. of rice. This can be represented by the following equation.

i 60 kg.x20=l ,200 kg.

It shall easily be thought to provide to the machine a larger horsepower of motor to increase its productivity. But, it has been impossible to do so up to date by reasons which shall be explained in relation with the embodiment of the present invention described in the following.

ln the drawing:

FIG. I is a sectional elevational view of the present invention machine;

FIG. 2 is a side sectional view of a FIG. 1 taken along the line Il-II of FIG. 1;

FIG. 3 is an explanatory view showing the working principle of a polishing roller and polishing chamber of the present invention machine; and

FIG. 4 is a perspective view of the polishing chamber supported by a clamping device in the present invention machine.

, Now, referring to the drawing, particularly to FIG. ll and 2, thereof, a grain-supplying hopper l is mounted on the upper wall of housing 7 and opens into a grain-receiving chamber 12 is provided with a damper 2 which controls passage of grains through the hopper into the grain-receiving chamber. Said damper is operable by the manipulation of lever 4 connected thereto by a rod 3. Grains supplied from the hopper fall into the chamber 12 by their own gravity, come into contact with a screw auger 5 rotatably mounted within said grain-receiving cham ber 12, and then are forwarded towards and into a grainpolishing chamber 9, having polishing space I3, in which a polishingroller is mounted rotatably and coaxially with the screw-feeding auger 5. Said screw auger and polishing roller are integrally rotated by a motor, not shown in the drawing, through a gearing when required. The polishing roller 6 is provided with a plurality of friction boards 6', for instance a pair of friction boards in the embodiment illustrated in the drawing, which project outwardly at a right angle from the outer circumferential wall of the roller substantially over its entire longitudinal length with 180 of angular distance therebetween.

The polishing chamber 9 made of perforated metallic sheet and having an octagonal shape at its cross section consists of two-semioctagonal bodies 9. Said two-semioctagonal bodies 9 are put together along their free longitudinal edges to form an elongated semioctagonal hollow grain-polishing chamber by a clamp device l0 having an inner circumferential configuration corresponding to that of the grain-polishing chamber 9. Said clamping device consists of two separable parts each pivoted at its lower end to a shaft 8 extending in parallel with the longitudinal axis of the grain-polishing roller 6 and grain polishing chamber 9 and fixed at its two ends to the sidewalls of the housing 7. Other end of each separable parts of the clamping device is removably fastened by a fastening device 1I fitted tothe inner upper wall surface of the housing 7 the device consisting ofa bolt andthe nuts 12, as shown in FIG. 2. In the embodiment shown in the drawing, such clamping device described above are employed at both ends of the grain-polishing chamber to support said chamber in place.

When the fastening devices are released and the separable parts of clamping device l0 are respectively turned outwardly about the shaft 8, the polishing chamber is removable from the housing 7 and foreign particles such as rice-brans adhered to the perforated polishing chamber during the grain-polishing operation can be removed.

Numeral l5 indicates an inlet for supplying air under pressure through openings 16 to an air passage 17 running coaxially and through the grain-supplying auger 5 and polishing roller 6. The air supplied into the polishing roller 6 is forced out from pores 18 provided n the circumferential surface surface of the roller 6 and communicated with the air passage 17 and works to blow out rice-brans through the perforated polishing chamber into the housing 7. Numeral 14 indicates a takeoff opening to discharge grains polished in the polishing chamber therefrom.

In a conventional grain-polishing machine of the type having the aforementioned constructions, which polishing of grains are performed by the friction given to the grains by a polishing roller in relation to its rotary positions against a polishing chamber, the polishing chamber is either cylindrical or of hexagonal configuration in its cross section, as far as the inventor knows. In the former type of polishing chamber, a high capacitor of motor could be employed, because the friction given to grains circulating held between the polishing chamber and the polishing roller is rather uniform and not large enough to give the grains a frictional resistance against the roller. The grains are, therefore, polished mainly by rubbing each other, whereby productive capacity becomes poor even when a high horsepower of motor is employed to drive the polishing roller.

While, in the latter type of polishing chamber, in which the minimum space between a hexagonal polishing chamber and polishing roller is about 6.2 mm. and the maximum space thereof about 3l mm. when the roller is 137 mm. in diameter, it is nearly impossible to provide the machine with a larger diameter of polishing roller and a larger horsepower of motor t0 drive the former without breakage or cracks of rices which are being subjected to a maximum rubbing friction by the roller and polishing chamber of hexagonal configuration.

In the present grain-polishing machine having the constructions described as above, however, it is possible to employ a larger diameter polishing roller and al larger horsepower of motor without producing breakage or cracks of grains and still with a high and positive hulling and polishing efficiency. As best shown in FIG. 3, even when a larger diameter of polishing roller 6 having its outermost diameter of about 170 mm. that is, a polishing roller having a diameter which can stand for a higher load given thereto accompanying with the employment of a larger horsepower of motor and a larger load given thereto accompanying with subjecting a larger amount of grains to polishing in a unit of time is employed, the distance between the polishing chamber 9 and the locus to be made by the driven polishing roller 6 can be kept to 37 mm. at its maximum as shown by the letter M in the drawing and to 9 mm. at its minimum as shown by the letter m, which assures to frictionally polish grains sometimes strongly and sometimes softly at an adequate value without giving breakage or cracks to the grains. A motor of more than 30 horsepower could safely be utilized in the machine, resulting in raising its capacity more than ten times of that of a conventional grain-polishing machine of this kind.

Iclaim:

l. A high-capacity grain-polishing machine comprising a grain-feeding auger and a grain-polishing roller of diameter at least 137 mm. with a plurality of friction boards projecting outwardly substantially at a right angle from the outer circumferential wall thereof with an equal angular distance therebetween, both of said auger and roller being driven by a motor of more than 30 hp., and a grain-polishing chamber housing coaxial about said grain-polishing roller and having an octagonal cross-sectional configuration..

2. A machine in accordance with claim l wherein said octagonal-polishing chamber comprises two-facing semioctagonal sections; said machine further comprising means to releasably clamp together said two facing chamber sections, said clamping means comprising a shaft parallel to the axis of said roller and located outside said chamber in a plane passing through the facing parts of said semioctagonal sections, a first pair of clamp members at one end of said chamber and pivotally mounted on said shaft and wherein each of said first n pair of clamp members is of semioctagonal shape and contacts 

1. A high-capacity grain-polishing machine comprising a grainfeeding auger and a grain-polishing roller of diameter at least 137 mm. with a plurality of friction boards projecting outwardly substantially at a right angle from the outer circumferential wall thereof with an equal angular distance therebetween, both of said auger and roller being driven by a motor of more than 30 hp., and a grain-polishing chamber housing coaxial about said grain-polishing roller and having an octagonal cross-sectional configuration.
 2. A machine in accordance with claim 1 wherein said octagonal-polishing chamber comprises two-facing semioctagonal sections; said machine further comprising means to releasably clamp together said two facing chamber sections, said clamping means comprising a shaft parallel to the axis of said roller and located outside said chamber in a plane passing through the facing parts of said semioctagonal sections, a first pair of clamp members at one end of said chamber and pivotally mounted on said shaft and wherein each of said first pair of clamp members is of semioctagonal shape and contacts the outer surface of one of said semioctagonal sections, a second pair of clamp members at the other end of said chamber and pivotally mounted on said shaft and wherein each of said second pair of clamp members is of semioctagonal shape and contacts the outer surface of one of said semioctagonal sections, and means for holding each pair of clamp members together about said chamber. 